A BIACORE Surface Plasmon Resonance (SPR) instrument is requested to support the ongoing studies of macromolecular structure and dynamics at the University of Texas Health Science Center at San Antonio (UTHSCSA). There is an urgent need for SPR at the UTHSCSA that is essential to the data collection needs of our user base. This instrument will support research that requires state-of-the-art SPR instrumentation to define and characterize macromolecular interactions in a diverse array of research problems. The proposed instrument will greatly enhance the research of six major users. Common features of this diverse group of users include: 1) An immediate need for on-site surface plasmon resonance instrumentation, 2) Research problems- dedicated towards answering fundamental biological/biophysical questions, and 3) Funded NIH research programs which have specific requirements for SPR. Research in the following specific areas will be significantly enhanced by the proposed instrument: (1) Coated Vesicle Dynamics (Lafer), (2) Chromatin Structure (Hansen), (3) Flavin and Heme-Mediated Enzyme Systems (Masters), (4) Cytokine Receptor Signaling (Hinck), (5) Metaloenzyme Structure and Function (Hart), and (6) Multisubunit Enzyme Systems (Henn). The proposed instrument has the strong endorsement of the institution. The University will provide resources to cover instrument maintenance and the salary for the SPR Laboratory operator. The SPR Laboratory will be an essential component of the Macromolecular Dynamics Core of the Center For Biomolecular Structure Analysis (CBSA). Other components of this core include analytical ultracentrifugation, dynamic light scattering, large particle gel electrophoresis, microcalorimetry and various types of uv-vis and fluorescence spectroscopy. Other core laboratories in the CBSA include an X-Ray Crystallography Laboratory, Nuclear Magnetic Resonance Laboratory, Protein Laboratory, Mass Spectrometry Laboratory and Microbial Fermentation Laboratory. Among the major user group are the directors of the Analytical Ultracentrifugation Laboratory (Hansen), X-Ray Crystallography Laboratory (Hart), and Nuclear Magnetic Resonance Laboratory (Hinck), greatly facilitating interactions between the SPR Laboratory and the other complementary technologies of the Center.